SU1374273A1 - Apparatus for presenting graphic information on crt screen - Google Patents

Abstract

The invention relates to automation, radiolocation and computing, and can be used in display devices and graphic information retrieval devices. The purpose of the invention is to improve the accuracy of the device, which is achieved by introducing the element 22 and the sensor 23 of the control coordinates and the corresponding functional connections, which ensures the display of the reference image in the area of the CRT 16 optically connected to the sensor 23 forming the relative offset of the corrected image, correcting codes from adders 11 and 12 increments are summed in adders 9 and 10, as a result of which the entire image on the screen of the CRT 16 shifts in the required direction, eliminating the existing error image. 1 il. (/)

Description

11374273

refers to automatism

ke, radar, and computing and can be used in display devices and graphic information retrieval.

The purpose of the invention is to improve the accuracy of the device.

The drawing shows the functional diagram of the device.

The device contains the first 1, second 2, third 3 and fourth 4 transducers code - voltage, the first 5 and second 6 sawtooth voltage generators, the first 7 and second 8 formers of the sweep voltage, first 9 and the second 10 adders, the first 11 and second 12 increment, coordinate adders, first 13 and second 14 decoders, video signal generator 15, CRT 16 with deflection system 17, delay element 18, OR element 19, prohibition element 20, pulse driver 21, image element 22, and sensor 23 control coordinates of the image .

Position 24 denotes the control input of the device, and positions 25-30 denote the information inputs of the device from the first to the sixth.

The voltage level at the information inputs of the generator 5 and 6 determines the rate of change of the sawtooth voltage at the outputs (voltage steepness). The duration of the signal at the control inputs of the generators 5 and 6 determines the time during which the sawtooth is formed (the open-state time of the key element determines the time of the continuous running of the saw-tooth voltage).

The sweep voltage formers 7 and 8 provide for the conversion of the input voltage to voltage or current acting on the deflecting system 17 (electrostatic or electromagnetic) of the CRT 16 and controlling the movement of the electron beam across the screen.

The arrival of a signal at the control input from 3 of the mapper 9 (10) prohibits the summation of the code arriving at its second information input, i.e., the output of the adder in this case. a signal passes, which is the sum of the codes arriving at the first and third information inputs.

five

The adders 11 and 12 increments of coordinates of the image of control points are accumulative-type adders. The first input of the increment adder is information, and the second is the control, i.e. allows writing information to the adder at the falling edge of the control signal.

Decoders 13 and 14 - combination type. The signal at the output of the decoder is generated only if codes of numbers corresponding to the coordinates (along the X axis or along the Y axis) of control points arrive at its inputs.

The video signal generator 15 extracts from the control signals received at its input signals of the point illumination control and the vector illumination control signals, since the duration of the signalformer 15 formed by these pulse signals is different. In pros-. To distinguish these signals from the backlight control, points can be transmitted, for example, by a negative voltage level - and vector control signals can be transmitted by a positive voltage level (i.e., the level perceived by the element OR 19 as a signal).

The delay element 18 provides for the delay of the input signal for a time, taking into account the inertia of the formation of the vector video signals by the shaper 15.

0

five

five

The element together with the element 18 of the delay and the connection between them form the inhibitor pulse generator, the duration of which covers the maximum possible duration of the video signal at the output of the imaging unit 15.

With prohibition element 20, the first entry is prohibitive.

Pulse generator 21 provides pulse formation with a delay relative to the input signal, taking into account the inertia of signal conversion in adders, (converter code - voltage), sweep voltage generator, deflection system of a CRT, as well as inertia of the former 15 in the process of forming the video signal of points.

The sensor 23 of the control coordinates is designed to form the codes of the relative coordinates X and Y of the reference image. In the simplest case, the sensor 23 is a coordinate matrix consisting of photosensitive elements, the outputs of which are connected to the inputs of combinational encoders of coordinates on the axes X and Y. The dimensions of the photosensitive element (more precisely, their pitch on the axes X and Y) are determined The minimum attainable value (or step) of image shift correction (minimum error of displacement) is applied. The number of photosensitive elements (more precisely, the product of their number by the step of positioning in a row or column) determines the maximum possible image displacement error in the device that can be compensated. The number of photosensitive elements in the coordinate line

image cops that are not control, but optically fall into the zone controlled by the photosensitive elements of the coordinate matrix). The coordinate matrix with the photosensitive elements of the sensor 23 control coordinates in the simplest case is placed under the CRT screen 16 in one place (for example, right on the screen surface with the edge) so that the image of the control point (the light of the circle) on the CRT screen approximately coincides with the central the photosensitive element of the coordinate matrix, and the axes of its coordinates X and Y coincided in direction with the axes of the X and Y coordinates of the image on the CRT screen, in order to eliminate the error in the formation by the sensor 23 of the control x coordinate when the control point picture (in the case of large sizes) It appears optically coupled

as the number of rows in the matrix, is chosen odd. The combinational encoders of the coordinates are designed in such a way that the illumination of the central of the photosensitive elements of the matrix leads to the formation of zero codes by the encoder of the coordinates X and Y. The illumination of the photosensitive element located relative to the central one

natal matrix (i.e., the number of columns), 25 | associated with several

nearby photosensitive elements of the coordinate matrix, the encoder sensor 23 may contain - the element of choice of one (for example, the minimum) coordinates from several.

The device works as follows.

Consider the operation of the device when the codes of the coordinates of the highlighted point (or the codes of the coordinates of the origin

or lower (along the Y coordinate), results in the displayed vector) are not

thirty

I to the formation of zero codes on the X axis and, respectively, codes -1, or. +1 on the Y coordinate. Illumination of a photosensitive element located relative to the central one. On two elements up and three. Left leads to the formation of a code on the X axis equal to +3, and on the Y axis equal to -2, etc. The codes of the encoder coordinate codes are generated on the leading edge of the control signal, which enters the sensor input 23 of the control coordinates. The sensitivity of the photosensitive elements of the coordinate matrix is chosen in such a way that they react to the point displayed on the CRT screen only at the moment of its illumination (at the moment of the video signal at the output of the imaging unit 15) and do not respond to its display due to the afterglow of the CRT screen (this does not affect the sensor 23 on ele30

0

five

0

five

 coordinates of the reference image. In this case, the decoders. 13 and 14 do not simultaneously form output signals, as a result of which the output of element 22 does not form a detection pulse of the code of the reference image coordinate, and therefore, delay element 18, element OR 19, prohibition element 20, pulse generator 21 and control coordinates sensor 23 The devices do not affect me. From an external device, such as a computer (not shown), the inputs X and Y of the highlighted point (or the coordinate codes of the beginning of the highlighted vector), respectively, arrive at inputs 27 and 28, which are unchanged (we assume that at the initial time; time at the outputs of adders 11 and 12 increments, zero codes are present) pass through the adders 9 and 10 and arrive at the inputs, converters 3 and 4 code are the voltage, from whose outputs the values of analog voltages corresponding to the input codes arrive at the first inputs of the drivers 7 and 8sweeps, the output signals of which affect the deflecting system 17, as a result of which the electron beam is output to the required-point of the CRT screen 16 (or to the initial position of the displayed vector). In the case of a point emitting, at the next time point, the control input 24 from an external source receives a pulse of negative polarity for starting the imaging unit 15, as a result of which a short backlight pulse is generated at its output, affecting the CRT modulator 16, and on its screen is displayed point.

In the case of vector illumination from an external device, simultaneously with the codes supplied to inputs 27 and 28, the coordinate codes X and Y of the end points of the displayed vectors arrive at inputs 25 and 26, respectively, so that the corresponding voltage codes are formed at the outputs of the converters 1 and 2 of the code-voltage levels. voltage. At the next moment, the control input 24 from an external device receives a positive polarity signal, starting up the generators 5 and 6 of the sawtooth voltage and driver 15. The voltage level at the information inputs of the sawtooth generator 5 and 6 determines

. the rate of change of the output sawtooth voltage, and the duration of the signal at input 24 is the time during which the sawtooth voltage is formed and the illumination time of the CRT beam 16. From the outputs of the generators 5 and 6 of the sawtooth voltage, a linearly varying voltage acts through the formers 7 and 8, the sweep voltage to the deflection system 17, as a result of which a vector of a predetermined length and direction is displayed on the screen of the CRT 16. .

If it is necessary to shift the displayed information (shift of the display center), a command from an external device, such as an operator, to the inputs 29 and 30 receives, respectively, the coordinate codes X and Y of the shift of the center of the image, which

summed in adders 9 and 10 with the codes of the coordinates of the highlighted point or with the codes of the coordinates of the beginning of the displayed vector arriving at inputs 27 and 28, as a result of which a corresponding shift of the displayed information occurs on the screen of the CRT 16. Consider the process of formation

corrective image voltage.

To inputs 27 and 28 periodically from, the external device along with the X and Y coordinate codes of the displayed points

The X and Y coordinate codes of the image checker are received with the X and Y coordinate codes of the beginning of the vectors. If, when entering the inputs 27 and 28 of the coordinate codes X and Y displayed

0 points or the beginning of the displayed vector, only one of the coordinate codes, such as the coordinates .X (Y), coincides with the code of the reference image along this coordinate, then the output

5 a corresponding decoder 13 (14) coordinates a pulse is formed, which, however, will not pass to the output of element 22, since the latter is closed at the second (first) input to zero

Q level of voltage and output of the decoder 14 (13) coordinates.

If the input codes 27 and 28 receive the coordinate codes X and Y, which are the coordinate codes of the reference image, the output signals are generated simultaneously both at the output of the decoder 13 coordinates and at the output of the decoder 14 coordinates. As a consequence, the output of the element 22 forms a pulse arriving at the permissive input of the prohibition element 20 and indicating that the coordinate signals in the input signals coincide with the coordinate codes of the reference image. Her- . whether the indicated coordinate codes are not the coordinate codes of the control, the image, but are only random codes of coordinates of the origin of the displayed vector,

0 then the delay element 18, the element OR 19 and the element 20 of the ban are included. Since the arrival of codes of the coordinates of the beginning of the displayed vector is always accompanied by the arrival at the control input 24 of a pulse of positive polarity, which ensures the operation of the control inputs of the generators 5 and 6 pilo5

five

figurative voltage, then this pulse simultaneously arrives at the first code of the element OR 19 directly and at its second input from the output of the element 18 of the delay. As a result, at the output of element 1Sh 19, a pulse is generated, which arrives at the prohibition input of the element 20 prohibition and prohibits the formation of pulses at its output for the entire time the vector is illuminated on the screen of CRT 16.

Thus, the signal at the output of the inhibition element 20. is formed only if the coordinates of the reference image are received at the inputs 27 and 28 of the device.

The signal from the output of the element 20 is fed to the input of the pulse generator 21 and to the control inputs of adders 9 and 10. The arrival of a pulse at the control inputs of adders 9 and 10 causes it to be switched in such a way that codes without the output of adders 9 and 10 are generated. taking into account the codes present at the input 29 and 30 of the device (without taking into account the external image shift codes). In other words, the outputs of the adders 9 and 10 are traversed by the unchanged codes of the X and Y coordinates of the control, respectively, of the image (we assume that there are zero codes at the outputs of the adders 11 and 12). Coordinate codes. The reference image from the outputs of adders 9 and 10 is fed to the inputs of the converters 3 and 4, the voltage code corresponding to the analogue. beep voltages from the outputs of which, through the formers 7 and 8, of the sweep voltage, affect the deflection system i 1 7, outputting the beam of the CRT 16 to a given point on the screen. The shaper 15 then forms a pulse arriving at the CRT modulator 16 and providing a reference image on the screen of the CRT 16. The reference image is illuminated in place of the CRT screen, which is optically coupled to the photosensitive elements of the sensor 23 control coordinates.

The pulse former 21 from the output signal coming from the output of the prohibition element 20 generates a pulse, along the leading edge of which, on the first and second outputs of the sensor 23 of the control coordinates, relative respectively

eight

X and Y (taken with

five

0

five

d

0

five

0

five

0

five

minus) displacement of the reference image on the CRT 16 screen of the relative geometric center (central element) of the photosensitive matrix of the sensor 23. In the absence of an error in the display path, the relative coordinate codes X and Y of the reference image are zero and the codes (at the initial time corrective action codes are zero) at the outputs of the adders 11 and 12 do not change. If there is an error in the display path, the reference image on the screen of the CRT 16 does not coincide with the geometric center of the photosensitive matrix of the sensor 23, as a result of which at its first and second outputs, the coordinate codes X and Y (taken with a minus sign) displace the reference image relative to the desired position. . Along the trailing edge of the pulse from the pulse generator 21, algebraic summation of these codes of the relative displacement of the coordinates X and Y, respectively, in adders 11 and 12 with the previous (in this case zero) values of the codes of the displacement of the image occurs. The summary code of the corrective action along the X and Y coordinates is supplied from the outputs of the adders 11 and 12, respectively, to the third information inputs of the adders 9 and 10, where they are constantly summed with the current codes of the displayed information (including the control one), as a result of which all the displayed information is shifted by the CRT 16 screen in the X and Y coordinates in the right direction, as the code of the corrective action tends to reduce to zero the display error (i.e., combine the reference image with the geometric center of the light) sensitive sensor matrix 23). If, for any reason, the magnitude of the corrective action was not determined quite accurately, then by the falling edge of the next pulse at the output of the pulse generator 21 pulses (this pulse will be generated in the event of subsequent receipt of the control image codes at inputs 27 and 28) and 12 form a new updated corrective action code.

each of the coordinates with new relative offset codes of the reference image coordinates (formed by sensors 23). The refinement of the correction codes at the outputs of the adders 11 and 12 leads to a more accurate shift of the image on the screen of the CRT 16 in the right direction. This process continues until the corrective action codes at the outputs of the adders 11 and 12 nullify the available error in the information display path. Similarly, the error caused by fluctuations in the network voltage, aging of the elements, their temperature instability, etc., is eliminated, which ensures high accuracy in displaying information in the proposed device.

Claims (1)

Invention Formula A device for displaying graphical information on the screen of a cathode ray tube, containing the first and second voltage code converters, whose inputs are the first and second information inputs of the device, respectively, and the outputs are connected to the information inputs of the first and second sawtooth voltage generators, respectively. the inputs of which, the input of the video signal conditioner, the first input of the OR element and the input of the delay element are the control input of the device, the output of the delay element It is connected with the second input of the OR element, the output of which is connected to the prohibiting input of the inhibiting element, the first and second adders, the first information inputs of which are respectively the third and five The fourth information inputs of the device, the fifth and sixth information inputs of which are respectively the second information inputs of the first and second adders, the third information inputs of which are connected respectively to the outputs of the first and second adders of coordinate increments, the outputs of the first and second adders are respectively connected to the inputs of the third and fourth Converters code - voltage, the outputs of which are connected respectively to the information inputs of the first and second drivers on p scan voltage controlled vkody guides which are respectively connected to the outputs generato0 moat sawtooth voltage, and outputs - a deflection system CRT, a modulator which is connected to the output of the video signal, the first and second decoders and shaper. 5 pulses, characterized in that, in order to improve the accuracy of the device, it contains an AND element and a sensor of reference coordinates optically connected to a CRT screen, the outputs of which are connected respectively to the information inputs of the first and second adders of coordinate increments, the control inputs of which the sensor input of the control coordinates: dinat is connected to the output of the pulse former, the input of which and the control inputs of the first and second adders are connected to the output of the inhibiting element, the permitting input of which is connected to the output building elements and pervsh and second inputs of which .soedineny respectively to the outputs of the first and second decoders, the inputs of which are connected respectively to the third and fourth information inputs. 0 five 0 five